Meta tags are placed in the head of HTML documents (web pages), as they can be read by some search engines. These tags are not visible to the viewer of your web pages. When a search engine indexes your web page, correctly added Meta tags can help your web site position in the index. A listing under your chosen keywords for instance may mean your pages are found sooner by people searching using those search terms. With the addition of the description tag you can choose your site's description for the index, instead of the search engine using the text from your web page to make up your site description.